Patients who have Type II diabetes and diabetic kidney disease were recruited for this study. The study is evluating the safety and efficacy of the study drug, irbesartan, compared to placebo (sugar pill) or amlodipine on kidney fucntion by looking at the amount of protein in the urine and other laboratory measurements of kidney function. The study drug is a member of a new class of drugs which are designed to lower blood pressure by blocking the action of angiotensin II, a naturally occurring substance in the body that raises blood pressure. The action of this class of drugs is similar to that of a class of drugs called angiotensin II converting enzyme (ACE) inhibitors, which are standard treatment for high blood pressure. One ACE inhibitor, captopril, is a prescription medication available to treat diabetic kidney disease through mechanisms other than lowering blood pressure in Type I Insulin-Dependent diabetics. No study has yet been able to demonstrate a benefit from medication therapy (other than blood pressure lowering) on kidney disease from Type II diabetes. This study is designed to evaluate if irbesartan has the same effect on the kidney in Type II diabetics with high blood pressure as captopril has in the Type I diabetic population with high blood pressure. The effects of amlodipine (another drug being evaluated in this study which belongs to the class of drugs called calcium channel blockers) on the kidney are unknown. The purpose of this study is to evaluate the safety and effectiveness of irbesartan compared to conventional blood pressure medications and placebo on kidney disease due to type II diabetes by looking at the amount of protein in the irine and other laboratory measurements of kidney function. Amlodipine and Irbesartan are already approved by the FDA.